The Primary Measure of Efficacy Was the Percent Change in the "Average Pain for the Past 24 Hours" Numeric Pain Rating Scale (NPRS) Score From Baseline During Weeks 2 to 12. [ Time Frame: Weeks 2-12 ] [ Designated as safety issue: No ]

Efficacy was assessed by daily Numeric Pain Rating Scale (NPRS) capturing "average pain for the past 24 hours" for painful HIV-associated neuropathy area(s) at approximately 9 PM every evening throughout the 12-week study period. The NPRS is an 11-point scale (0 to 10) with 0 indicating no pain and 10 indicating the worst possible pain.

Up to 4 NGX-4010 patches of 280 cm^2 each were applied to the feet (2 per foot) for 60 minutes.

Other Name: the brandname of NGX-4010, 8% capsaicin patch is Qutenza.

Experimental: NGX-4010, 30 minutes

Drug: NGX-4010, 8% capsaicin patch

Up to 4 NGX-4010 patches of 280 cm^2 each were applied to the feet (2 per foot) for 30 minutes.

Other Name: The brandname of NGX-4010, 8% capsaicin patch is Qutenza.

0.04% conc. capsaicin patch, 60 min.

Drug: 0.04% capsaicin patch

Up to 4 control patches of 280 cm^2 each were applied to the feet (2 per foot) for 60 minutes.

Other Name: NGX-4010

0.04% conc. capsaicin patch, 30 min.

Drug: 0.04% capsaicin patch

Up to 4 control patches of 280 cm^2 each were applied to the feet (2 per foot) for 30 minutes.

Other Name: NGX-4010

Detailed Description:

Study C119 was a multicenter, randomized, double-blind, controlled evaluation of the efficacy and safety of NGX-4010 for the treatment of painful HIV-associated neuropathy. Eligible subjects had painful HIV-associated neuropathy resulting from HIV disease and/or antiretroviral drug exposure in both feet, with average numeric pain rating scale (NPRS) scores during screening of 3 to 9 (inclusive). Up to four patches covering an area of up to 1120 square centimeters could be used during a single treatment administration in this study. Subjects were randomly assigned to receive active NGX-4010 patches (8% capsaicin) or low-concentration control patches (0.04% capsaicin) identical in appearance, at doses (patch application duration) of either 30 or 60 minutes, according to a 2:1:2:1 allocation scheme.

Subjects could be on stable chronic oral pain medication regimens, but could not be using any topical pain medications on the affected areas. NPRS scores for the average pain in the past 24 hours were recorded daily in the evening, beginning on the day of the Screening Visit (usually on Day -14). Subjects continued to record NPRS scores in a take-home diary from the evening on the day of treatment through the evening before the Termination Visit at Week 12. Subjects returned for interim follow-up visits at Weeks 4 and 8 following study treatment.

Eligibility

Ages Eligible for Study:

18 Years and older (Adult, Senior)

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Documented evidence of HIV-1 infection

Documented diagnosis of painful HIV-associated distal symmetric polyneuropathy resulting from HIV disease and/or antiretroviral drug exposure To be confirmed based on symptoms of pain, burning or dysesthetic discomfort in both feet for at least 2 months prior to Screening Visit, AND absent or diminished ankle reflexes OR at least one of following: distal diminution of vibration sensation or pain or temperature sensation in legs

Average NPRS scores during screening period of 3 to 9, inclusive

Life expectancy of 12 months or longer per Investigator's judgment

Intact, unbroken skin over painful areas to be treated

If taking chronic pain medications, be on stable regimen for at least 21 days prior to Day 0 and willing to maintain medications at same stable dose(s) and schedule throughout study

Unavailability of effective rescue medication strategy for subject, such as unwillingness to use opioid analgesics during study treatment or high tolerance to opioids precluding ability to relieve treatment-associated discomfort as judged by investigator

Active substance abuse or history of chronic substance abuse within past year or prior chronic substance abuse (including alcoholism) judged likely to recur during study period by investigator

Recent use (within 21 days preceding Day 0) of any topically applied pain medication, such as non-steroidal anti-inflammatory drugs, menthol, methyl salicylate, local anesthetics including Lidoderm® (lidocaine patch 5%), steroids or capsaicin products on painful areas

Started or stopped treatment with one or more neurotoxic antiretroviral agents (ie, didanosine [ddI], zalcitabine [ddC], or stavudine [d4T] during 8 weeks prior to Day 0

Participation in previous clinical trial in which subject received either blinded or open-label NGX-4010

Current use of any investigational agent or Class 1 anti-arrhythmic drugs (such as tocainide and mexiletine)

Evidence of another contributing cause for peripheral neuropathy, e.g., current uncontrolled diabetes mellitus (HbA1c≥9%) or history of diabetes mellitus preceding onset of HIV-associated neuropathy (HIV-AN); hereditary neuropathy; vitamin B12 deficiency (B12 level ≤200pg/mL at screening); or treatment within 90 days prior to Screening Visit with any drug that may have contributed to sensory neuropathy

Hypertension, unless adequately controlled by medication

Significant ongoing pain from other cause(s) that may interfere with judging HIV-AN related pain

Significant medical conditions (including active malignancy defined as treatment required in last 5 years) that in opinion of investigator would interfere with ability to complete study or evaluation of AEs

Recent significant medical-surgical intervention that in judgment of Investigator would interfere with ability to complete study or evaluation of AEs; examples include to major surgery, or receipt of immunosuppressive therapy within 3 months prior to Day 0

Evidence of cognitive impairment including dementia that may interfere with subject's ability to complete daily pain diaries requiring recall of average HIV-associated neuropathy pain level in past 24 hours

Contacts and Locations

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Please refer to this study by its ClinicalTrials.gov identifier: NCT00321672